So far I am very happy with what I have seen. PCI is
certainly not dead,
though it is getting harder to find. I could not find any Xeon boards with
PCI slots for example... even if I had wanted to pay the extra.
In my company we have many Dell computers with Xeon processors and PCI slots.
for examples models : Dell precision T3500, T1700, T3600
As they are "professional" computer, high price comes with it. The
latest models made by Dell still have one PCI slot.
Could be found second hand I think.